Why not? If the journal published a lot of good/popular/highly cited articles, then the numbers can change quite a bit from one year to another.
I think there is the IF list for 2009 somewhere on this site. For 2008, I also have 7.28

Theory is when we know everything and nothing is working. Practice is when everything is working and nobody knows why. Here, we combine theory and practice. Nothing is working and nobody knows why.

It also shows that the impact factor doesn't mean too much -- publish good papers, and they'll get cited. It could also go the other way -- as they're fond of pointing out in financial circles, past performance is no guarantee of future results.

I am also getting the feeling that most IFs increased during the last years, but I suspect this is because more and more journals are included in the ranking .... the more journals - the more citations - the higher the IF

A man cannot be too careful in the choice of his enemies. (Oscar Wilde)